Wire manufactured by additive manufacturing methods

ABSTRACT

Systems and methods for the manufacture of a solid wire using additive manufacturing techniques are disclosed. In one embodiment, a fine powdery material is sintered or melted or soldered or metallurgically bonded onto a metal strip substrate in a compacted solid form or a near-net shape (e.g., a near-net solid wire shape) before being turned into a final product through forming or drawing dies.

RELATED APPLICATIONS

The present application is a continuation of U.S. Ser. No. 15/373,230filed Dec. 8, 2016 (U.S. Pat. No. 10,688,596), which claims priority toand benefit from U.S. Application No. 62/269,247, filed Dec. 18, 2015,now expired. The above-identified application is hereby incorporatedherein by reference in its entirety.

BACKGROUND

Solid wire and tubular wire co-exist in the marketplace since each typeof wire has its own pros and cons.

Solid wire provides a cost advantage and a consistency and precision indiameter, core composition, deposition, helix, cast, wire placement,feedability, surface chemistry, arc characteristics, etc. However, solidwire costs are driven primarily by the green rod cost that is largelydependent on economies of scale, thereby making it difficult formanufacturers to produce custom solid wire in smaller lot sizes due tothe sourcing barrier of steel billets raw material from steel mills.

Tubular wire, characterized by a conglomerated or blended powder in thecore and a metal sheath surrounding the core, benefits from changingchemistry for smaller lot sizes. However, tubular wire is difficult toproduce when the finished diameter is too small (e.g., 0.030″ or less).Work hardening from folding the thin sheath may require annealing. Forout of position welding, synergic pulse waveform may need to bedeveloped for its increased melt-off rate and metal transfer behavior.It may have variation in powder density, homogeneity, compactness, andsheath thickness and may trap air and moisture inside the wire. Thus itmay not be as consistent as solid wire in metal transfer and otherwelding characteristics. Reduced columnar strength may present wirefeeding challenges. Seamless tubular wire overcomes some issues of theseamed tubular wire such as uniform outer surfaces for copper platingand being orientationally insensitive to deformation from drive rollpressure. However, seamless wire is more costly to produce due to batchfilling and high frequency welding of the seam and also due to the batchannealing operations required to mitigate the work hardening effect. Oneissue characteristic of tubular wire is that there is a ballooningphenomenon in which the molten metal at the end of the wire increases insize larger than the wire diameter and dangles chaotically under thewire before detachment. Known as globular transfer, presumably due tothe expansion of trapped air, it creates instability, a less focusedarc, and shallow penetration. Another issue is that the instantaneousmelt-off rate may not be as uniform as solid wire because thecompactness or density of the powder in the core of tubular wire is notas homogeneous as the integral metal core of the solid wire. A furtherissue is the non-uniform heating and melting of the solid sheath andpowder core, where the outer sheath may melt first, sometimesasymmetrically, and where the core material (e.g., tungsten carbide) isleft to be dropped into the weld pool un-melted in solid form andbounced off the pool surface without being absorbed into the pool. Whatis needed is a system and a method that can economically produce customchemistry or composition wire in solid form or a customized form tocombine the merits of both solid wire and tubular wire.

BRIEF SUMMARY

Methods and systems are provided for producing a wire (e.g., a solidwire, other types of wire) with custom chemistry or composition usingadditive manufacturing methods substantially as illustrated by and/ordescribed in connection with at least one of the figures, as set forthmore completely in the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an embodiment of powder based feedstock 3-D printing onto amoving strip substrate according to the present disclosure.

FIG. 2 shows an embodiment of wire based feedstock 3-D printing onto amoving strip substrate according to the present disclosure.

FIG. 3 shows an embodiment of additive manufacturing of solid wire withlaser metal deposition (LMD) according to the present disclosure.

FIG. 4 shows an embodiment of additive manufacturing of solid wire withLMD according to the present disclosure.

FIG. 5 shows an embodiment of work-in-progress (WIP) wire processingaccording to the present disclosure.

FIG. 6 shows the progression of build layers from original strip tonear-net shape prior to further drawing and heat-treatment stages toproduce the finished wire according to an embodiment of the presentdisclosure.

FIG. 7 shows an embodiment of a printed wire with solid skin in theexterior and structured interior (e.g., a honeycomb structure as anexample for illustration) according to the present disclosure.

FIG. 8 shows an embodiment of a printed wire with lengthwise patterns ofinterior structural variation or compositional variation according tothe present disclosure.

FIG. 9 shows an embodiment of the near-net shape wire being drawnthrough a drawing die according to the present disclosure.

DETAILED DESCRIPTION

Aspects of some embodiments according to the present disclosure relateto the art of manufacturing consumable filler metal that can be used inwelding, joining, cladding, soldering, surface overlaying, hard facing,and brazing processes, for example. Filler metal can be used as aconsumable electrode in some types of joining or surface processing, oras a non-electrode filler rod in other types of joining or surfacingprocesses. Although circular geometry wire is most commonly used, othershapes such as flat or rectangular ribbon or strips are also used inpractice. Thus the term “wire” in the present disclosure applies broadlyto shapes other than round shaped wire, and the term “welding” in thepresent disclosure broadly encompasses other related processes.

Some embodiments of the present disclosure relate to systems and methodsfor manufacturing solid welding wire by additive manufacturingtechniques.

Some embodiments of the present disclosure provide for additivemanufacturing or three-dimensional (3D) printing, for example, beingused with sintering technologies including selective laser sintering andmicro-induction sintering. These sintering technologies are based oncompacting powder and forming a solid mass by heating and/or by applyingpressure without totally melting the powder particles. Laser andinduction heating, for example, can be used as a heating source. Otherheat sources or processes such as electron beam, TIG, reciprocating wirecontrolled short circuiting MIG, resistance seam welding, frictionwelding and ultrasonic welding can be employed for additivemanufacturing.

Some embodiments provide that a fine powdery material is sintered ormelted or soldered onto a metal strip substrate in a compacted solidform or a near-net shape (e.g., a near-net solid wire shape) beforebeing turned into a final product through forming or drawing dies.

FIG. 1 shows an embodiment of a system and method for manufacturingsolid welding wire by additive manufacturing techniques. The system 100includes, for example, a substrate transport system 110, a materialsource 120, and a heat source 130. In some embodiments, the materialsource 120 delivery and heat source 130 are integrated into one processhead. Referring to FIG. 1, the substrate transport system 110 includes,for example, one or more pulleys 140, which might include motorizeddrive rolls, that are arranged to pull a wire substrate 150 through thematerial source 120 and past the heat source 130. In some embodiments,the material source 120 includes, for example, one or more powder beds160. The material source 120 provides the materials for deposition onthe wire substrate 150. The heat source 130 includes, for example, oneor more lasers 170 and one or more optical devices 180 (e.g., lenses,mirrors, filters, etc.). The heat source 130 is configured to providethe heat that assists the deposited materials to form a solid on thewire substrate 150. In some embodiments, the pressure around the wiresubstrate 150 is also controlled to further facilitate the solidifyingof the deposited materials with the wire substrate 150.

In some embodiments, the wire substrate 150 includes a metal strip as asubstrate. The metal strip can be flat or curved. For example, the metalstrip can be a flat belt, a C-shaped strip, a U-shaped strip, a V-shapedstrip, or a semi-circular shaped strip.

In some embodiments, the material source 120 can include a dam or awiper that is configured to control the height of the powder on top ofthe wire substrate 150. The dam can be positioned in front of oroperationally before the heat source 130. Since the wire substrate 150can change direction as it passes through the power bed 160, the wiper(or dam) can be arranged in a position that corresponds to the movementof the wire substrate 150. In one example, the wiper (or dam) can bestationary and set to a certain gap above the moving substrate where thegap corresponds to the build-up height. In another example, the singlepowder bed 160 in FIG. 1 may be split into separate powder chambers sothat the height of each powder bed 160 can be separately managed foreach lap that the metal strip of the wire substrate 150 passes under theheat source 130 (e.g., a laser).

In some embodiments, the wire substrate 150 can be pre-heated prior tobeing exposed to the sintering heat source. In some embodiments, thepre-heating phase may be accomplished by induction, radiated heat, etc.without melting the powder.

In some embodiments, a gravity drop is arranged to apply the powder. Ina gravity drop, the powder is dispensed from a hopper above the movingwire substrate 150 at a certain rate and dropped or belt fed onto themoving conveyor of the wire substrate 150 ahead of the heat source 130.A catch pan or bed can be arranged below for collecting and recyclingthe excess powder.

In some embodiments, the heat source 130 can include one or more lasersand the laser power distribution can be arranged so that the build-up isof a line or rectangular shape, for example, that matches with the widthof the next layer of build-up. Other beam patterns such as a cross, astar, a polygon, a ring, an oval, an infinity sign, a twin-spot, atriple-spot, a quad-spot, etc. can be used to control the solidificationrate, microstructure, defect, discontinuity, and residual stress of thebuild-up; and work hardening and columnar strength of the WIP wire. Thepatterns may be generated optically without moving parts or bymechanical oscillation of optics. The laser energy distribution can betop hat, Gaussian, multimode, or others. Laser power may be controlledbased on the melting temperature of the powder. For example, higherpower density can be used for metal powder and lower power density canbe used for flux compounds. In some embodiments, the heat source 130 caninclude one or more micro-induction heating heads that employ highfrequency induction heating transducers powered by one or more radiofrequency power supplies. The induction heating head can include amagnetic flux concentrator that is configured to apply a spatiallycompact magnetic field to sinter small granular particles/powder intosolid form onto a metal substrate or strip of the wire substrate 150.

In some embodiments, the heat source 130 can include, for example, oneor more lasers 170 and one or more optical devices 180 (e.g., lenses,mirrors, filters, etc.). The laser 170 and the optical device 180, whichis configured to manipulate the laser beam from the laser 170, aresimplified for illustration in FIG. 1. The laser beam emitted by theheat source 130 can be arranged so that it is shared among multiplework-in-process (WIP) wires as the wires are progressively built-up overmultiple passes through the material source 120. In some embodiments,the optical device 180 can include, for example, one or more of thefollowing: a refractive, transmissive, or reflective objective focusinglens; a structured light pattern projection; a beam splitter; agalvanometer; a mirror; and a closed-loop servo positioning system. Insome embodiments, the optical device 180 can incorporate a variablecollimator and/or zoom homogenizer to adjust zoom on-the-fly and controlthe focal position and energy density. In some embodiments, the laser170 and/or the optical device 180 are stationary. In some embodiments,the laser 170 and/or the optical device 180 move during operations. Forexample, the optical device 180 can move in a periodic pattern (e.g.,swivel periodically) so that the laser beam is directed to differentparts of the powder bed 160 or the wire substrate 150. The opticaldevice 180 can also include, for example, shutters, apertures, purginggas nozzles, air knifes, and cover slides.

In some embodiments, a wire vibration or wire actual position detectorcan be configured at or near the wire surface to be built up and used tosense wire position prior to exposing the wire substrate 150 to the heatsource 130, either before or after the wiper/dam. The actual position ofwire substrate 150 is sent to a system controller to guide the opticaldevice 180 (e.g., the optics) to aim the laser at the incoming wiresubstrate 150. The actual wire position can be used, for example, in afeedback control of a galvo-mirror system for beam positioning andfocus. A 500 W to 5 kW ytterbium fiber laser can be configured to fusefine metallic powders onto the substrate with a spot size commensuratewith the width of the desired build layer. Some embodiments contemplateusing other lasers including, for example, a disk laser, a semiconductorlaser, a diode laser, direct diode lasers such as TeraDiode (e.g., usingwavelength beam combining with free-space optics) or coherent beamcombining or side-by-side beam combining to increase beam brightness,other rare-earth element doped fiber laser, double-clad fiber laser, acrystal laser, an Nd:YAG laser, a gas laser, a CO₂ laser, a continuouswave laser, a pulsed laser, an excimer laser, and a femtosecond laser.Different laser may be chosen for different types of wire material, wiresize, and other wire properties.

In operation according to some embodiments, a wire substrate 150 ispulled by pulleys 140 of the substrate transport system 110 through thepowder bed 160 of the material source 120. The powder bed 160 can be apowder feedstock or bed as is used in three-dimensional (3D) printing.Powder is deposited on the wire substrate 150. A stationary wiper or damin front of or before the heat source 130 controls the height of thepowder or powder level by sweeping away or leveling the powder depositedon the wire substrate 150 as the wire substrate 150 passes under or bythe stationary wiper or dam. As the wire substrate 150 moves through thepowder bed 160, the optical device 180 focuses the laser beam from thelaser 170 to one or more locations in the powder bed 160 to heat thepowder deposited on the wire substrate 150. By controlling the heat, thewire speed and possibly the pressure, the powder deposited on the wiresubstrate 150 is sintered or melted or soldered into a solid wire form.In some embodiments, the wire substrate 150 can change directions foreach pass through the powder bed 160 in which successive layers arebuilt onto the wire substrate 150. Through each pass, the shape of thebuilt-up layers progressively changes into an approximately roundedshape or near-net shape. The near-net shape wire 150 can then be turnedinto a final product wire by passing the near-net shape wire 150 throughforming or drawing dies. FIG. 9 shows an embodiment of the near-netshape wire 150 being drawn through a drawing die 190 (or a drawing platein another embodiment), for example, to reduce the wire diameter, toshape the wire, and to form the final wire product. Although consideredin final product form, some embodiments contemplate baking, and/oradding a coating (e.g., copper) and/or arc stabilizers (e.g., potassiumor sodium) or other steps to the final wire product to prevent oxidationand to provide lubrication.

Because the wire substrate 150 after additive manufacturing is near-netshape, the amount of diameter reduction from subsequent drawing benchescan be significantly reduced. As a consequence, the hardening andannealing process can be reduced or eliminated in some embodiments. Thenear-net shape WIP wire improves the manufacturability of special alloysof high carbon equivalent and/or high hardenability and small diameterfine wire with less possibility of wire break in manufacturing.

FIG. 2 shows another embodiment of additive manufacturing of solid wireusing wire feedstock. In this embodiment, the material source 120employs a wire feeding system 200 instead of (or in addition to) apowder bed 160 as the feedstock of additive material. The wire feedingsystem 200 can include, for example, a wire supply 210, a feeder 220(e.g., drive wheels), and a heater 230. Some embodiments contemplateusing a rod instead of wire as a material feedstock. Another heat source240 can optionally be employed. The heat source 240 can be, for example,a resistive, inductive heater. FIG. 2 also shows that each pass of thewire substrate 150 has its own wire feeding system 200 and, optionally,its own heat source 240.

In operation, the wire feedstock is pulled by the feeder 220 from thewire supply 210 and fed through or by the heater 230 for deposition ontothe wire substrate 150. The heater 230 provides heat to make the wirefrom the wire supply 210 “hot” before deposition onto the wire substrate150. In some embodiments, the heater 230 heats wire substrate 150 sothat wire feedstock is melted or incorporated on contact with the wiresubstrate 150. It is also possible that the four instances of wiresupplies 210 in FIG. 2 are made of different compositions enablingflexible manufacturing for producing different chemistry WIP wires fromthe same production line simply by programming the selective combinationof wire supplies from the bank of wire suppliers.

In some embodiments, the heater 230 is part of a welding torch that usesa controlled short circuiting process with reciprocating wire feed fromthe feeder 220 to draw an arc by lifting depositing wire from the wiresubstrate 150 and to form a short circuit by plunging the wire feedstockinto the substrate melt pool. In this case, most of the heat isgenerated when the arc is present.

In some embodiments, a laser, a tungsten inert gas (TIG) arc, or aplasma arc, for example, can be used as the heat source with wire feedfrom the feeder 220 to supply additive material. The wire being fed fromthe feeder 220 can be un-heated (i.e., a cold wire), or, alternatively,the wire can be pre-heated (i.e., a hot wire). The wire being fed fromthe feeder 220 can be solid wire, or tubular wire with metal sheathoutside and powder inside.

FIG. 3 shows an embodiment of additively manufacturing solid wire usinglaser metal deposition (LMD). The LMD system 290 has an LMD head 300that coaxially delivers the laser beam 310, gas 320 (e.g., shieldinggas) and powder 330. The powder 330 can be conveyed by gas (or blown)and/or by gravity towards the wire substrate 150 that is movingunderneath the LMD head 300. LMD is a process that uses a high energydensity beam 310 (e.g., a laser beam) to melt the wire substrate 150 aspowder 330 is fed into the melt. Although a laser beam 310 is shown,some embodiments can use other heat sources such as an electron beam ora plasma arc. The powder 330 melts to form a build-up that ismetallurgically fused to the wire substrate 150. The process head 300typically has a cone shaped end in which the powder 330 is conveyed bygas towards the substrate 150 where the laser beam 310 is focused on.The head 300 can be configured to project multiple powder jets onto thesubstrate 150. Each powder jet can be fed by powder feedstock ofdifferent chemistry. FIG. 3 shows an arrangement of four LMD heads 300.Each head 300 adds a new layer onto the wire substrate or WIP forgradual build-up. Preferably, in some embodiments, the deposit materialis fused onto the end of the WIP wire in a flat position (e.g., WIP wireend pointing up) so that the powder 330 is conveyed in a downwardposition. The powder flow rate can vary, for example, from 1 to 100g/min., depending on the WIP wire size and the laser power. In someembodiments, a fiber laser can be selected and the laser power can rangefrom 500 W to 10 kW. The gas flow rate can range from 2 to 10 L/min.Although FIG. 3 shows an embodiment of a coaxial head 300, someembodiments provide that the powder 330 can be delivered non-coaxiallyfrom the side of the laser beam or even externally with respect to thehead 300.

FIG. 4 shows another embodiment of additively manufacturing solid wireusing laser metal deposition (LMD). The build-up is on one end of thewire (or axially), and the deposition rate or the buildup rate matcheswith the take-up rate by rollers to remove the WIP wire away from theLMD process head. Although FIG. 4 illustrates LMD for printing wireaxially, other printing processes such as controlled short circuit withreciprocating wire feed using an arc welding process with wire feedstock(or a bank of feedstocks) is also possible. Some embodiments useelectron beam direct manufacturing or electron beam additivemanufacturing, with either powder feedstock or wire feedstock, to printWIP welding wire axially in vacuum.

FIG. 5 shows an embodiment of laser processing of WIP wire. In someembodiments, the laser processing system 340 is configured to modifysurface properties and/or geometry of the wire substrate 150 (e.g., aWIP wire) without powder or a material source 120. In some embodiments,the heat source is used to bond metal strips together and/or to closethe seam of WIP wire. The system 340 includes, for example, thesubstrate transport system 110 and the heat source 130. Referring toFIG. 5, the substrate transport system 110 includes, for example, one ormore pulleys 140 that are arranged to pull the wire substrate 150 pastthe heat source 130.

In some embodiments, the heat source 130 includes, for example, one ormore high energy density beam heat sources 170 (e.g., lasers) and one ormore optical devices 180 (e.g., lenses, mirrors, filters, etc.). Theheat source 130 can be configured to modify surface properties and/orgeometry of the wire substrate 150 (e.g., a WIP wire) without powder,for example.

In some embodiments, one or more lasers 170 can be used for surfacemarking and/or texturing, for example, to reduction the friction orcontact force between the wire and the liner when the wire is pushedand/or pulled through the liner (e.g., during a welding operation). Thelaser 170 can be used to modify the wire stiffness (e.g., tendency forwire to buckle), asperity-to-asperity contact between the wire and theliner, and a coefficient of friction to improve wire to liner pressuredistribution and thus improve wire feedability, for example, during awelding operation. Feedability can be affected, for example, by frictionforces or contact forces between the wire and the liner.

In some embodiments, the laser 170 can introduce ridges in the range of20-160 μm, for example, which along with boundary lubrication, reducefriction fluctuation which can increase line and torch tip life inwelding operations. In some embodiments, the laser 170 (e.g., afemtosecond laser) can induce periodic surface nanostructures (LIPSS)which lowers the friction coefficient compared with a smooth surface.

In some embodiments, the laser 170 can be used in subtractive micro holedrilling or micromachining to create cavities on the exterior of thewire in order to reliably retain the proper amount of surface additivessuch as arc stabilizers (e.g., potassium or sodium) or lubricants forfeedability or chemicals for wire identification to be detected bychemical sensors in the wire delivery devices (e.g., torch, feeder,conduit, etc.) during welding.

In some embodiments, the laser 170 can be used to introduce residualstress (e.g., compressive and/or tensile stress) in certain patterns sothat elastic/plastic deformation can be retained for wire cast andhelix. When large enough residual stresses are retained, it is possiblefor the welding wire to make a designed spin motion after it exits thecontact tip in the welding torch and to cause the arc to spin.

In addition to the processes described with respect to FIGS. 1-4, someembodiments contemplate using other variations of additive processesincluding, for example, cold spray, high velocity oxy-fuel spray,twin-wire electric arc spray, and flame spray with either powder orwire. In FIG. 4, for example, the LMD heads 300 can be replaced by coldspray/thermal spray heads for additively manufacturing welding wire. Incold spray, the gas (e.g., N₂, H₂, or air) and can be preheated in therange of 400-600° C. by a 4-15 kW heater with a pressure in the range of250-500 psi to accelerate powder particles at supersonic speed onto theWIP wire substrate 150. Some embodiments contemplate combining coldspray with a laser beam so that after the powder is sprayed on, thebuild-up is further heated or sintered or melted or soldered by thelaser beam.

FIG. 6 shows an embodiment of a progression of layers using additivemanufacturing techniques to form a round solid wire. A C-shapedsubstrate 150, for example, is employed. On a first pass through thematerial source 120, a first layer 250 is deposited and formed into asolid WIP wire with larger cross-sectional area. On a second pass, asecond layer 260 is deposited and formed into a solid WIP wire with aneven larger area. On subsequent passes, a third layer 270 and a fourthlayer 280 are deposited and formed into an even larger solid WIP wire.The third layer 270 and fourth layer 280, for example, are deposited andformed into a rounded near-net wire shape.

The progression of layers illustrated in FIG. 6 is a simplifiedprogression of a WIP wire. A C-shaped substrate 150 is shown, but someembodiments contemplate using other types of substrates such as a flatstrip and using drawing dies to form the round bottom shape. Someembodiments also contemplate using U-shaped or V-shaped substrate 150.Although four passes are shown, more or less than four passes may bedesired in practice. For example, ten laps in which each lap adds 0.1 mmcan be used to create a 1 mm build thickness. Further, some embodimentscontemplate that each layer can have different or custom compositionrather than a uniform composition for all layers. With respect to theprocess in FIG. 1, for example, each powder bed chamber 160 can have adifferent powder mixture. With respect to FIGS. 2-4, for example, eachwire feedstock can have a different wire chemistry or can be of adifferent wire type.

FIG. 7 shows an embodiment of a wire manufactured by the additivemanufacturing techniques in which the wire has a smooth and continuousexterior skin and a honeycomb interior. Some embodiments contemplateusing other shapes (e.g., triangles, quadrilaterals, polygons, arcs,curves, etc.) instead of or in addition to the honeycomb shape. Inaddition to completely “solid” wires, some embodiments contemplatemanufacturing a porous wire with a one or more cavities in the middleusing additive manufacturing techniques, while maintaining a smoothexterior (or skin) for efficient wire feeding. In one embodiment, ahollow wire with a ring cross-section can be produced.

Such custom-made, additively manufactured wires can find a number ofapplications. For example, a custom-made wire with a porous interior canbe used for gas metal arc welding (GMAW) welding and can increase theelectrode extension heating effect with higher resistivity; increasedeposition with reduced heat input, reduced manganese fume, and reducedundercut; change arc width/shape/stability, puddle fluidity, beadprofile and penetration profile; propensity towards defects anddiscontinuity; and possibly reduce the threshold for spray transitioncurrent allowing lower rating and lower cost power sources for the samegauge base metal and duty cycle welding and reduced electric powerconsumption. Larger outside diameter (OD) porous solid wire, forexample, can be welded at a much lower current than same wire with acompletely solid interior. Larger OD diameter can be used with internalribs for added structural integrity against buckling for wider arc (yetlower welding current) to dramatically increase operator skillsforgiveness or fit-up tolerance. Instead of a hollow interior, someembodiments contemplate a more elaborate interior structure, such asperiodic hollow compartments separated by solid walls (e.g., honeycombstructures, etc.) to increase structural rigidity or stability for thesubsequent drawing process or for the feeding process. By changing theporousness of the interior, the resistivity can be adapted for a givenlength and outer diameter.

In some embodiments, the porous interior of the solid wire can be usedas a conduit for a gas medium. In welding applications, the gas can beconventional shielding gas, or assist gas with special additives toreduce diffusible hydrogen or reduce aluminum cathodic cleaning track,or pulsed pressure or constant high pressure gas for increasing puddledepression and weld penetration. High pressure air or gas delivered bycarbon wire as a conduit can be used for high efficiency carbon arcgouging or cutting.

FIG. 8 shows an embodiment of an additively manufacture wire in whichthe wire has length-wise patterns of structure or composition. In someembodiments, different material sources 120 can be arranged in anadjacent configuration to produce, in successive layers, length-wisepatterns of structure or composition. Referring to FIG. 8, the wire cancomprise the length-wise pattern of sections A, B, and C repeated over aparticular length. Sections A, B, and C can represent, for example,three different material compositions (e.g., chemical compositions). Inaddition, sections A, B, and C can represent different structuralcompositions (e.g., solid, honeycomb, and hollow). Yet further, sectionsA, B, and C can have different physical properties (e.g., differentmelting points, different magnetic properties, different densities,different masses, different conductivity, different resistivity, etc.).

In one embodiment, an internal wire structure and or materialcomposition comprises a pattern that repeats at a fixed length. In someapplications, as the wire moves under a magnetic sensor or opticalsensor, for example, the pattern may be used to sense actual wire feedrate. The magnetic sensor can be a contact-less sensor to measure actualwire speed. This is in contrast with using a roller, for example, thatis pressed in contact with wire to sense wire speed.

Some applications of this type of wire according to some embodimentscontemplate synchronizing the welding waveform or laser power with theinterior wire structure sensed by the non-contact magnetic or opticalsensor to improve metal transfer in arc/laser welding, cladding,hot-wire or cold-wire TIG or plasma, and brazing with wire. For example,the additively manufactured wire can have a band of carbon steelcomposition with high aluminum alloy content, interleaved with a band ofcarbon steel composition of low aluminum alloy. The controlled shortcircuiting with reciprocating wire feeding welding process can beemployed in such a way that the high aluminum band is burned off orconsumed in the arc phase, while the low aluminum band is dipped intothe weld pool in short circuit without subjecting to arc heating. Inanother example, bands of high silicon can be interleaved with bands oflow silicon where the high silicon bands are delivered with asynchronized torch weave or wire spin to the weld toes with higherpuddle fluidity (and better toe geometry and fatigue life), whilemaintaining the overall silicon level to the wire chemistryspecification. Further, in another example, bands of low martensitictransformation temperature chemistry wire or LTTW (e.g., 10% Cr-10% Ni)may be delivered synchronously to the weld toes to induce compressivestress at the toes and thus increase fatigue life of the weldedstructure without making the entire wire out of the expensive LTTWchemistry for carbon steel welding. Other synchronization between wirepattern and arc characteristics/metal transfer mode is alsocontemplated, such as synchronizing arc polarity and arc current levelwith the repeatable bands in the wire. In one example ofsynchronization, bands of expensive alloying elements (e.g., Ni, Ti, Mo,rare-earth metals, etc.) can be transferred during the “electrodenegative” or straight polarity phase of the AC waveform during welding,so that they are substantially transferred into weld the metal withoutbeing burned up in the arc. Geometrical features in the interior orexterior of the solid wire can be sensed and used to signal to thewelding power source (e.g., a welding power supply) to flip the polarityof its output.

The cost of metal in powder form is usually much lower than in coil(e.g., green rod) form. The additional cost of additive manufacturingequipment depreciation cost can be offset by the savings from rawmaterial in solid wire filler metal manufacturing.

In some embodiments, internal wire structure can include a “code” forwire identification (e.g., wire diameter, wire type, etc.). The code canbe a geometric pattern of varying internal structure, cross-sectionalarea, or mass. As the wire moves under a magnetic sensor, the code canbe read to identify the wire type, wire diameter, etc.

In some embodiments, solid wire is manufactured with a solid interiorcore made of different chemistry than the solid exterior so that themelting temperature of interior is substantially lower than that of theexterior to reduce the “pencil” shaped wire end when it is melted in theGMAW arc. This allows for pure argon shielding gas GMAW welding withoutoxygen or carbon dioxide in the shielding gas and yet maintains processstability to achieve desired weld ductility.

Some embodiments provide for the pattern printing of different wirechemistry along the length of the wire. For example, some embodimentscontemplate printing a pattern of alternating low melting pointcomposition wire “slice” and high melting point wire segment. When thetrailing low melting point wire slice melts, the leading high meltingpoint wire falls off into the weld pool, thus increase melt-offefficiency. Energy is not wasted, for example, attempting to melt thehigh melting point wire so that it can fall into the weld pool. Thisimproves heat efficiency by reducing heat input into the work piece andcan benefit from increased deposition rates.

Some embodiments provide for the manufacture of metal matrix compositewire, nanoparticle wire, and tungsten carbide cladding wire previouslynot possible in solid wire form.

Although some embodiments contemplate that the drawing process occursafter the additive wire building process, some embodiments are not solimited. Some embodiments contemplate mixing the drawing process (e.g.,wire forming) with the additive process, or contemplate intertwiningthem. For example, after one pass of build-up, the WIP wire can bepulled through drawing die(s) (or drawing plates) to shape the WIP wiremore precisely for the next lap of build-up. In particular, roller diedrawing or roll drawing can be used to turn near-net shape wire fromadditive manufacturing process into finished dimension wire, withreduced work hardening, drawing forces, die wear and wire breaks.Drawing dies may be submerged in water for wet draw. Some embodimentsprovide that the drawing die does not have a round hole but a profile(e.g., an intermediate shape (with flat top) such as in FIG. 6) with ablock or Turk's-head machine in the drawing bench. To reduce drawingforce, some embodiments use roller die drawing or roll drawing, insteadof fixed dies to convert shear friction into rolling friction. Inaddition to mixing additive deposition and drawing processes, someembodiments incorporate or mix in a subtractive process, and/or a heattreatment process such as inter-pass forming, cooling process, stressrelief process and annealing process, integral to the additivedeposition build-up process.

Some embodiments provide for in-situ metrology, in-situ process control,and in-situ quality control in additive solid wire production. Someembodiments provide in line non-contact inspection including, forexample, laser ultrasound to detect bulk porosity for interiorintegrity, and micrometer measurements for WIP wire exterior dimensionand shape, which can be part of adaptive process control. A temperaturesensor or a pyrometer camera can be used to measure temperature and sizeof a melt area, and thermal gradient can be determined for predictingmicrostructures and propensity for defect.

Some embodiments provide in-situ self-diagnostics mechanisms. Sensorscan be deployed to detect laser protective cover lens cleanlinesscondition, leaky resonator, shift of laser focus, etc. to provide analert for preventative maintenance. A calorimeter can be used in thearea of additive manufacturing for measuring actual laser power, powerdensity, beam quality (e.g., beam parameter product or BPP, or M²), andfor checking against power set-point. If a discrepancy is found, anincrease in laser power set point to match, or a shutdown to checkoptics and beam delivery can be triggered. Power level sensors can beused and wire feedability and feeding force sensors may be built intothe system for potential shutdown and preventative maintenance.

Some embodiments provide for building a near-net shaped solid wire that,for example, effectively reduces the number of draw downs. In someembodiments, the near-net shaped wire has a porous internal structureand an external surface. In some embodiments, the near-net shaped wirehas a hermetically sealed exterior. In some embodiments, the near-netshaped wire has different compositions or constitution that repeat in alength-wise direction of the near-net shaped wire. In some embodiments,the near-net shaped wire has different physical properties that repeatin a length-wise direction of the near-net shaped wire. In someembodiments, the finished solid wire is consumed in an electric arc orhigh energy density beam for welding, brazing, or cladding. In someembodiments, the finished solid wire is consumed in an electric arc orhigh energy density beam for cutting or gouging.

Some embodiments provide a system for manufacturing a wire or awelding-type filler metal wire. The system can include, for example, anLMD head or a direct manufacturing electron beam or an electric arctorch that is configured to deposit a material and to heat the depositedmaterial to additively manufacture a near-net shaped wire in an axialdirection of the near-net shaped wire; a transportation systemconfigured to axially move the wire away from the laser metal depositionhead, wherein the transportation system and the laser metal depositionhead are matched in speed; and a plate assembly or a die assemblyconfigured to draw down a diameter of the near-net shape wire into afinished wire. In some embodiments, the LMD head is configured tocoaxially provide a laser beam, a material, and a shielding gas. In someembodiments, the near-net shaped wire axially builds up.

Some embodiments provide a method for manufacturing a wire or awelding-type filler metal wire. The method can include, for example, oneor more of the following: moving a metal substrate, by a transportersystem, through or by a material source system; depositing a layer ofmaterial on the metal substrate during each pass through or by thematerial source system; building via sintering or melting the layer of adeposited material on the metal substrate after each pass through or bythe material source system; and forming the finished solid wire bydrawing the built material together with the metal substrate through adrawing plate assembly or a drawing die assembly. In some embodiments,the deposition of the layer of material includes depositing apredominantly metal powder on the metal substrate during each passthrough a powder bed that includes the predominantly metal powder, andwherein the powder bed is part of the material source system. In someembodiments, the deposition of the layer of material includes feeding afeeder wire to the wire substrate and heating the feeder wire and/or thewire substrate so that the feeder wire solidifies with the wiresubstrate. In some embodiments, the deposition of the layer of materialincludes depositing different materials or compositions in a repeatedpattern in a length-wise direction of the wire substrate.

Some embodiments provide a system for manufacturing a wire or awelding-type filler metal wire. The system can include, for example, atransporter system configured to move a work-in-progress filler metalbuild under a heat source; a material source system configured toprovide a source material that is added to a substrate or a previouslybonded material by the heat source over one or more passes to build anear-net shaped solid wire; and a plate assembly or a die assemblyconfigured to draw down to ensure a diameter or a cross-sectional areaof the near-net shape solid wire into a finished solid wire.

Some embodiments provide a system for manufacturing a wire or awelding-type filler metal wire. The system can include, for example, anLMD head or an electric arc torch or an electron beam that is configuredto heat a metal substrate and to deposit a material onto the heatedmetal substrate to additively manufacture a near-net shaped wire; atransportation system configured to move the metal substrate under theLMD head or the electric arc torch or the electron beam; and a plateassembly or a die assembly configured to draw down a diameter of thenear-net shape wire into a finished wire.

Some embodiments provide a system for manufacturing a wire or awelding-type filler metal wire. The system can include, for example, atransporter system configured to move a metal substrate under a heatsource; a material source system configured to provide a metal oxide, acarbide, a silica, or a flux or a high temperature nanoparticle that isbonded to the metal substrate by the heat source over one or more passesto progressively increase a cross-sectional area of a near-net shapedsolid wire; and a plate assembly or a die assembly configured to allow askin pass of the near-net shape solid wire into a finished solid wire.In some embodiments, the material source system can provide a two ormore of the following: a metal material, a metal oxide, a carbide, asilica, a flux, high temperature nanoparticles, and other non-metallicmaterials. The plate assembly or the die assembly can reduce diameter ofthe near-net shape solid wire by less than ten percent. In someembodiments, the plate assembly or the die assembly might notsubstantially reduce the diameter of the near-net shape solid wire whenforming the finished solid wire.

Some embodiments provide a system for manufacturing a wire or awelding-type filler metal wire. The system can include, for example, atransporter system and a plate assembly or die assembly. The transportersystem can be configured to move a wire-in-progress (WIP) wire under aheat source. The heat source can be configured to modify a surfaceproperty or a geometry of the WIP wire. The plate assembly or the dieassembly can be configured to draw down a diameter of the WIP wire intoa finished solid wire. The heat source can include, for example, a highenergy density beam heat source or a laser. The heat source can beconfigured to provide surface marking or texturing on the WIP wire;provide micro hole drilling or micromachining to create cavities in theWIP wire; and/or introduce residual stress in particular patterns in theWIP wire.

Some embodiments provide an integrally built or formed wire, ribbon, orstrip. One or more embodiments can include one or more of the following:an interior portion that is configured to be porous or to have one ormore cavities; an interior portion that configured to providegeometrical patterns of discontinuity; an interior portion that isconfigured to provide, axially or cross-sectionally, a chemical orcompositional variation pattern; an exterior portion that is configuredto provide cavities; an exterior portion that is configured with surfacetextures or nanostructures other than smooth; the wire, the ribbon, orthe strip that is configured to provide compression or tension residualstress patterns; the wire, the ribbon, or the strip that is configuredto provide stiffness patterns; the wire, the ribbon, or the strip thatis configured to provide elastic and plastic deformation patterns; andthe wire, the ribbon, or the strip that is configured to providelengthwise variation of a cross-sectional area with a pattern for anon-contact or magnetic sensing of the wire feed rate or codes for awire type and a size. In some embodiments, the wire, ribbon, or stripdoes not have powder constituents, or wherein the wire, ribbon, or stripis not built-up by mechanical layering or swaging. In some embodiments,the wire, ribbon, or strip is made using additive manufacturing orthree-dimensional (3D) printing. In some embodiments, one or moreproperties of the wire, ribbon, or strip is achieved by a high energydensity beam as a heat source. In some embodiments, the wire, ribbon, orstrip is configured as filler metal for welding, joining, cladding,soldering, or brazing.

Some embodiments provide a method for manufacturing a wire or awelding-type filler metal wire. The method can include one or more ofthe following: depositing a powder, a wire, or a strip as a rawmaterial; heating the raw material with a high energy density beam; andfusing the raw material into a WIP wire. In some embodiments, the highenergy density beam includes one or more of the following: a laser beam,an electron beam, and a plasma arc. In some embodiments, the high energydensity beam is used to fuse the exterior seam of the wire. In someembodiments, the interior of the solid wire is integrally bondedtogether and does not include a loose powder.

While the present methods, processes, and systems have been describedwith reference to certain implementations, it will be understood bythose skilled in the art that various changes may be made andequivalents may be substituted without departing from the scope of thepresent methods, processes, and systems. In addition, many modificationsmay be made to adapt a particular situation or material to the teachingsof the present disclosure without departing from its scope. Therefore,it is intended that the present methods, processes, and systems not belimited to the particular implementations disclosed, but that thepresent methods, processes, and systems will include all implementationsfalling within the scope of the appended claims.

What is claimed is:
 1. A system for manufacturing a welding-type fillermetal wire, comprising: a transporter system configured to move awork-in-progress filler metal build under a heat source; a materialsource system configured to provide a source material that is added to asubstrate or a previously bonded material by the heat source over one ormore passes to build a near-net shaped solid wire; and a plate assemblyor a die assembly configured to draw down to ensure a diameter or across-sectional area of the near-net shape solid wire into a finishedsolid wire.
 2. The system according to claim 1, wherein the diameter ofthe near-net shape solid wire is reduced by less than ten percent by theplate assembly or the die assembly.
 3. The system according to claim 1,wherein the substrate or the previously bonded material includes a metalstrip.
 4. The system according to claim 1, wherein the substrate or thepreviously bonded material includes a powder, a flux, a wire, or a rod.5. The system according to claim 1, wherein the transporter systemincludes one or more pulleys that move the substrate or the previouslybonded material.
 6. The system according to claim 1, wherein thetransporter system includes one or more motorized drive rolls.
 7. Thesystem according to claim 1, wherein the heat source includes one ormore of the following: a laser source, an induction heating source, anelectron beam source, and an arc.
 8. The system according to claim 1,wherein the finished solid wire is consumed in an electric arc or highenergy density beam for welding, brazing, or cladding.
 9. The systemaccording to claim 1, wherein the finished solid wire is consumed in anelectric arc or high energy density beam for cutting or gouging.
 10. Thesystem according to claim 1, wherein the transporter system continuouslyor periodically moves the substrate or the previously bonded material.11. The system according to claim 1, wherein the material source systemincludes a powder bed, wherein the transporter system moves thesubstrate or the previously bonded material multiple times through thepowder bed, and wherein each time through the powder bed causes adeposition of a layer of material in powder form on the substrate or thepreviously bonded material.
 12. The system according to claim 1, whereinthe heat source sinters or melts the deposited layer of metal and anon-metallic material onto the substrate or the previously bondedmaterial.
 13. The system according to claim 1, wherein the materialsource system includes a wire feeding system, and wherein the wirefeeding system provides a feeder wire to the substrate or the previouslybonded material such that the feeder wire melts and solidifies with thesubstrate or the previously bonded material.
 14. The system according toclaim 1, wherein the near-net shaped wire has a porous internalstructure and an external surface.
 15. The system according to claim 1,wherein the near-net shaped wire has a hermetically sealed exterior. 16.The system according to claim 1, wherein the near-net shaped wire hasdifferent compositions or constitution that repeat in a length-wisedirection of the near-net shaped wire.
 17. The system according to claim1, wherein the near-net shaped wire has different physical propertiesthat repeat in a length-wise direction of the near-net shaped wire. 18.The system according to claim 1, wherein the near-net shaped wire hasdifferent physical structures that repeat in a length-wise direction ofthe near-net shaped wire.
 19. The system according to claim 1, whereinthe substrate or the previously bonded material is initially a C-shaped,U-shaped, or flat metal strip.
 20. The system according to claim 1,wherein the source material includes metal or metal oxide powdersincluding or more of the following: iron, niobium, vanadium, zirconium,titanium, molybdenum, boron, rare-earth metals, aluminum, nickel,magnesium, manganese, and chromium.